Power generation and cooling capacity enhancement of natural gas processing facilities in harsh environmental conditions through waste heat utilization

• Published in: International journal of energy research Vol. 38; no. 15; pp. 1921 - 1936
• Main Authors: Eveloy, Valérie, Rodgers, Peter, Popli, Sahil
• Format: Journal Article
• Language: English
• Published: Chichester Blackwell Publishing Ltd 01.12.2014; Wiley; Hindawi Limited
• Subjects: absorption refrigeration; Applied sciences; CCP; cogeneration; Combined power plants; Cooling; Energy; Energy conservation; Energy. Thermal use of fuels; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; gas turbine; Installations for energy generation and conversion: thermal and electrical energy; Natural gas; Persian Gulf; Power generation; Power plants; Refrigeration; Waste heat; waste heat utilization; waste heat utilization; CCP; Cooling; Cogeneration; Power production; Absorption refrigeration; Gas turbine; Waste heat; Natural gas; Combined power plant
• ISSN: 0363-907X; 1099-114X
• DOI: 10.1002/er.3197

SUMMARY Most natural gas (NG) producers in the Persian Gulf face increasing challenges in meeting their domestic gas demands and therefore seek to reduce their NG consumption. Concurrently, the on‐site power generation and cooling capacities of local NG processing facilities are constrained by extreme climatic conditions. A combined cooling and power scheme based on gas turbine (GT) waste heat‐powered absorption refrigeration is techno‐economically assessed to reduce the NG consumption of a major gas processing plant in the Persian Gulf. The scheme utilizes double‐effect water‐lithium bromide absorption refrigeration activated by steam generated from GT exhaust gas waste heat to provide both GT compressor inlet air and process gas cooling. Based on a thermodynamic analysis, recovery of 150 MW of GT waste heat is found to enhance the plant cooling capacity by 195 MW, thereby permitting elimination of a 32.6 MW GT and existing cooling equipment. On‐site power generation is enhanced by 196 GWh annually through GT compressor inlet air cooling, with energy efficiency (i.e., 64%) improved by 35% using cogeneration relative to the existing power generation plant. The overall net annual operating expenditure savings contributed by the combined cooling and power system are of $US13 million to 34 million based on present and projected local utility prices, with an economic payback period estimated at 2 to 5 years. These savings translate to approximately 94 to 241 MMSCM of NG per year, highlighting the potential of absorption refrigeration to both enhance the power generation and cooling capacity of hydrocarbon processing plants exposed to harsh environmental conditions and to realize substantial primary energy savings. Copyright © 2014 John Wiley & Sons, Ltd. The proposed cogeneration scheme, tailored to a major natural gas (NG) processing plant operating in high ambient temperature and relative humidity conditions in the Persian Gulf, is based on gas turbine waste heat‐activated absorption cooling. This scheme permits on‐site power generation to be enhanced by 196 GWh annually and process cooling capacity by 145 MW. Net annual operating expenditure savings are of $US13 million to 34 million, equivalent to 94 to 241 MMSCM of NG per year, with an economic payback period of 2 to 5 years. The scheme contributes to reduce dependence upon NG imports.